Problem: $ { \left[\begin{array}{rr}{0} & {4} \\ {4} & {1} \\ {-2} & {1}\end{array}\right]+\left[\begin{array}{rr}{3} & {0} \\ {3} & {0} \\ {-2} & {0}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{0}+{3} & {4}+{0} \\ {4}+{3} & {1}+{0} \\ {-2}+{-2} & {1}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{3} & {4} \\ {7} & {1} \\ {-4} & {1}\end{array}\right]}$